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This paper reports the synthesis of LiNi0.8Co0.15Al0.05O2 (NCA) cathode powders using a simple flame assisted spray pyrolysis (FSP) and a spray drying (SD) processes, in which metal salt precursors dissolved in glycerol were used for spraying. X-ray diffraction confirms that the NCA powders have a layered structure, with a low order of cationic mixing. Electron microscopy shows that the particles produced by FSP have a relatively smaller size and a smoother surface than that produced by SD. The NCA powder from the FSP process has an initial discharge capacity of 200.2 mAh/g in voltage range of 3.0–4.3 V at 0.1C. It shows very good capacity retention of 91.5% at 1C and 89.4% at 5C after 200 cycles. These results demonstrate that glycerol can replace water and be used as a solvent in spray processes to make cathode powders, promising a new environmentally-friendly synthesis route for battery powder materials production.

Porous alumina has been shown to be an excellent adsorbent for Congo Red (CR) dye. In this work, highly porous g-Al2O3 nanoshells were synthesized from alumina coated carbon black (CB) obtained from a new deposition technique and used for removal of CR dye from aqueous solutions. Adsorption experiments were conducted in a batch mode and a series of parameters were investigated, including contact time, initial dye concentrations, ionic strength and pH of the solutions. It was found that equilibrium for CR adsorption can be reached within 30 min, much faster than reported by other studies in the literature on similar adsorbents. It was also found that the adsorption capacity of Al2O3 nanoshells is 44.8 % higher than that of alumina/CB. The adsorption capacity of Al2O3 nanoshells was more favorable at lower pH, and the optimal adsorption ability was achieved at pH 4.0 with a removal efficiency at 98.6 %. The Al2O3 nanoshells have a maximum adsorption capacity of 370.4 mg g−1 (25 °C; pH 7; no salt added), better than or comparable to those reported in the literature. A pseudo-second-order kinetics model can best fit the kinetics of CR adsorption, which follows the Langmuir isotherm. The high adsorption capacity is attributed to the strong hydrogen-bonding interactions between the anionic dye and Al2O3 nanoshells surface as well as to the electrostatic interactions between CR dye and the Al2O3 nanoshells.

Nanocoatings on solids can be achieved by various processes, including sol-gel and atomic layer deposition. However, challenges remain for achieving uniform nanocoatings on nanoscale substrates at a large scale. Here, we report a versatile and fundamentally different technique, termed condensed layer deposition, for depositing conformal metal oxide nanocoatings on nanoparticles and nanofibers. This approach involves water in liquid hydrocarbons condensing as a nanoscale water film on the substrate surface, enabled by interfacial tension between polar water and nonpolar liquid hydrocarbons. Chemical precursors are then added, which react with the condensed water film to form a metal oxide nanocoating. We demonstrate this for titania, alumina, and niobia on substrates including carbon nanotubes, iron oxide particles and carbon black. Condensed layer deposition can achieve oxide nanocoatings on a variety of substrates with tunable thickness, in one pass, at room temperature. Nano-scale coatings are important for controlling the functional behavior of surfaces. Here, a deposition process in liquid hydrocarbons is reported for metal oxides, in which a thin water coating on the substrate reacts with chemical precursors, forming a nano-scale layer.

Electrooxidation of methanol was investigated on platinum catalyst supported on a double oxide nanocomposite of tin oxide clusters and carbon-doped titanium dioxide nanocoatings on carbon nanotubes. Formation kinetics of the oxygenated species ( OH) groups was dramatically enhanced in the catalyst with double oxide support. This leads to a much lower onset potential for adsorbed CO oxidation with a much enhanced bifunctional effect in tin oxide. The electrocatalyst demonstrated a higher forward peak current density in methanol electrooxidation than the electrocatalyst with single tin oxide or bare carbon as support. Binding energy shift in oxidation states was observed for the double oxide support catalyst and is attributed to strong metal support interactions. Doping with carbon in the titanium oxide enables backward electron donation, making the supported platinum more electron negative and stable. This study demonstrated a synergistic effect of combining bifunctional and electronic mechanisms with double oxide support in the enhancement of methanol electrooxidation.

International audience; Carbon nanotubes (CNTs) are synthesized by the flame fragment deposition (FFD) technique using Iraqi liquefied petroleum gas (LPG) as a source of carbon in a hand-made reactor at a low temperature (160 °C) without using a catalyst. Purification of the multi-walled carbon nanotubes (MWCNTs) is carried out using a two-step process consisting of sonication in 30 wt.% hydrogen peroxide (H2O2) solution at room temperature to remove amorphous impurities adhering to the walls of the CNTs and carbon nanoparticles (CNPs), followed by sonication in an acetone bath to remove the polyaromatic hydrocarbons (PAH) formed during the LPG gas burning. Comprehensive characterizations such as X-ray diffraction (XRD), atomic force microscopy (AFM), thermo-gravimetric analysis (TGA), and transmission electron microscopy (TEM) were conducted to verify the efficiency of the purification process. The results clearly demonstrated that this process is promising for the purification of the synthesized CNTs

Pt catalysts perform well in the oxygen reduction reaction (ORR), but they suffer weak bonding with carbon supports, leading to catalyst degradation. We introduce a fluffy titanium dioxide (TiO2) nanolayer with a very high specific surface area as support, made possible with a new condensed layer deposition technique. When Pt and SnO2 were incorporated in it as co-catalyst, a remarkable improvement in ORR onset potential was achieved at 930 mV vs RHE in sulfuric acids. The mass activity was 2.66 times that of Pt/C at 900 mV. The fluffy layer stabilized SnO2 and together, they enabled a pronounced ligand effect.